One-chip sensing device (biomedical photonic LSI) enabled to assess hippocampal steep and gradual up-regulated proteolytic activities

Neuropsin—A possible modulator of synaptic plasticity

“…The blockade of neuropsin activation critically stopped early phase LTP without any effect on basal synaptic transmission, and LTP-inducing tetanus was shown to activate proneuropsin to the active protease briefly after tetanic stimulation (Komai et al, 2000;Tamura et al, 2006Tamura et al, ,2008. These data can be interpreted as a sequential signaling cascade following four steps.…”

Implantable CMOS Imaging Devices

“…To overcome this difficulty, three types of imaging devices have been developed: a fiber endoscope [25][26][27][28][29], a head-mountable device [28][29][30], and a brain-implantable device [31][32][33][34][35][36], as shown in Figure 10.20. In the following sections, these devices are introduced, and the brain-implantable device is described in detail.…”

“…In order to address this issue, an implantable CMOS imaging device has been proposed and demonstrated. This device has a submillimeter/sub-second spatiotemporal resolution and has successfully been used to monitor the time course of serine protease activity inside a mouse hippocampus [31][32][33][34][35][36]. In the next section, the brain-implantable CMOS imaging device is discussed.…”

Implantable CMOS biomedical devices

“…However, this is difficult for current measurement methods, such as functional magnetic resonance imaging (fMRI), positron emission tomography (PET), and near infrared spectroscopy (NIRS) to meet both of these requirements, as shown in Figure 14 [31]. We have developed a new CMOS-based imaging device with a sub-mm, sub-second spatiotemporal resolution and have successfully demonstrated monitoring of the time course of serine protease activities inside the mouse hippocampus [6][7][8][9]. Through appropriate packaging, the developed device can be used for arbitrary depth imaging inside the mouse brain with minimal impact on brain function.…”

“…In this review, two typical examples of implantable CMOS devices from our research are described: retinal prosthesis devices [1][2][3][4][5] and brain-implantable devices based on CMOS technologies [6][7][8][9]. In retinal prosthesis devices, MEMS technologies with CMOS circuits have been used to realize a retinal stimulator based on a microchip array, and in brain-implantable devices, image sensor technology and MEMS have been combined to realize an ultra-compact device to be implanted in the deep brain of experimental small animals.…”